Bermudagrass (Cynodon spp. L. C. Rich) is one of the most important and widely used warm-season turfgrasses. It is adapted to the warm- and subtropic-climatic regions of the world. The turf-type Bermudagrasses are C.sub.4, perennials that originated in southeastern Africa. The common turf-type species of Cynodon include: Cynodon dactylon (L.) Pers. of dactylon Bermudagrass which is a tetraploid; and Cynodon transvaalensis (Burtt-Davy) or African Bermudagrass which is a diploid. The dactylon Bermudagrasses as a group are characterized by a relatively coarse leaf width and lower shoot density, while the hybrid bermudagrasses tend to have narrower leaf width and higher shoot density. Both are relatively low-growing via vigorous lateral stems, both rhizomes and stolons.
Putting greens in the warm, humid climatic regions of the United States are usually planted with Bermudagrass. There are two Bermudagrass varieties primarily used on putting greens today; Tifgreen (328), released in 1956 and Tifdwarf, released in 1965. Other varieties have been used regionally, but have not gained wide acceptance as the desirable characteristics of Tifgreen and Tifdwarf became more commonly known.
There are six basic components of turfgrass quality: (a) uniformity, (b) density, (c) texture, (d) growth habit, (e) smoothness, and (f) color.
For Bermudagrasses, the primary factor influencing uniformity and smoothness is inflorescence. Most bermudagrasses produce seedheads which rise above the canopy and are generally considered to be unslightly. For use on a putting green, it is desirable to have a variety which has very minimal seedhead formation.
One of the most important components of turfgrass quality is density. Of particular problem for bermudagrass greens is maintaining density at increasingly lower heights. With improvements in equipment and increasing sophistication of golfers, it is now common to find greens regularly mowed at 1/8of an inch. At this height, adequate density becomes critical in order to prevent sunlight from reaching the surface of the soil. When this happens, not only does weed invasion become more of a problem, but given the daily irrigation most greens receive, algae begins to grow on the soil. Algae growing on the putting green further harms the grass, which in turn loses even more density, creating a situation which often leads to thin spots or even bare ground on greens.
In order to accommodate the low mowing heights on a putting green, it is desirable to have a variety which exhibits a fine leaf texture and a vertical leaf orientation. Since greens are usually mowed only once daily, a variety with leaves which do not grow up too quickly would be beneficial in providing a uniform surface for golfers playing several hours after mowing. A variety which possesses rapid lateral growth would be able to more quickly recover from injury due to ball marks, scuffing, and equipment.
Turfgrass species and cultivars selected for putting greens must possess special characteristics including (a) a low, creeping growth habit and erect leaves, (b) tolerance to very close mowing of 0.2 inch (5 millimeters), (c) very high shoot density, (d) fine leaf texture, (e) uniformity, (f) freedom from excessive grain and thatch, and (g) good recuperative rate. Other features are also desirable, such as resistance to pest injury and tolerance to environmental, soil, and traffic stress. A dark-green color does not affect putting quality but does enhance the aesthetics of the course.